Body, Wheels, Axels

Axles and wheels shall be only as provided in the Official Grand Prix Pinewood Derby Kit.
You MUST use the block of wood provided. Purchasing pre-made bodies is NOT ALLOWED.
Wheels may be lightly sanded to smooth out molding imperfections on the tread area. This light sanding is the only modification allowed. Beveling, tapering, thin sanding, wafering, or lathe turning of the wheels is prohibited.
Axles may not be altered in any way except for polishing. Bending, angling, and or, beveling is prohibited and they must be placed in the predrilled axle wells already on the block.
The Axle wells can not be covered or filled and must be used for your wheel placement unless you get specific permission from the Cubmaster.
Wheel bearings, washers, bushings, and hub caps are prohibited.
The car shall not ride on any type of spring.
The car must be free-wheeling, with no starting device or other type of propulsion.

Length, Width, Clearance

The maximum overall width (including wheels and axles) shall not exceed 2-3/4 inches.
The minimum width between the wheels shall be 1-3/4 inches so the car will clear the center guide strip on the track.
The minimum clearance between the bottom of the car and the track surface shall be 3/8 inch so the car will clear the center guide strip on the track.
The maximum overall length shall not exceed 7 inches.
The wheel-base (distance between the front and rear axles) may not be changed from the kit body distance of 4-1/4 inches.

Going Straight

Axles must be put in straight front to back. That is square to the body. True the axles, don't trust the slots! If you have one, use a drill press to ensure all axles are straight. One of the front and two of the back should be measured to be the same height. Please inform the Cubmaster that alteration of the axle slot is needed.
After pressing in the axles, test the car for crooked wheels...roll it on the floor. If the wheels are on straight, the car should roll 8-10 feet in a fairly straight line. Should the car turn left or right, you need to tinker with the axle placement without removing them from the car body, until it rolls straight.
Do not put the axles in at the top of the groove. Put them in the middle. This lifts the car off the track a bit more and reduces the chance of rubbing on the center strip.
Glue the axles in place. Nothing is worse than having the wheel fall off as you cross the finish line, but make sure the axles are visible. The axle nail MUST be visible.
Once you match a wheel and axle together with graphite, keep them together. They wear into each other as a matched set.

Weight and Appearance

Weight shall not exceed 5 ounces. The reading of the official scale will be considered final. The car may be hollowed out and built up to the maximum weight by the addition of wood or metal only, provided the material is securely built into the body or firmly affixed to it. No liquids or loose materials of any kind are permitted in or on the car.
Details such as steering wheel, driver, spoiler, decals, painting, and interior details are permissible as long as these details do not exceed the maximum length, width, or weight specifications.
Cars with wet paint will not be accepted.

Inspection, Weigh-in, & Registration

Each car must pass a technical inspection before it may compete. Technical inspection and registration of cars will occur from 06:00 pm to 09:00 pm the night before the race.
The Inspection Committee shall disqualify cars that do not meet these rules. If a car does not pass inspection, the owner will be informed of the reason his car did not pass (too long, too heavy, altered wheelbase, or the like). Cars that fail the initial inspection may be modified for final inspection and registration.
To enter the race, cars must have passed inspection and be registered by the Final Inspection Deadline at 9:00 PM.
No cars may be altered in any way after it has been registered. Damage repair shall be allowed during the Derby only if it does not delay the race, but no modifications shall be allowed.
After passing inspection, no car shall be re-inspected unless repaired after damage in handling or in a race.
Unsportsmanlike conduct by any participant or spectator will be grounds for expulsion from the competition and/or the race area.

Note: The Race Starter will place the car on the track according to axle location. The back axle is nearest to the end of the car. The front axle is furthest away from the end of the car. This determines the direction the car will race unless the contestant clearly marks "Front" on the car.

Weigh-In

Get the weight as close to the 5 -ounce limit as possible. Add the last little bit of weight with lead tape from the golf shop. This can be trimmed with scissors at the last minute. Remember, the official scale may not weigh the same as yours.
Everyone has an opinion on where to put the weight. The belief is that the weight needs to be predominantly in the rear so that gravity can act upon the weight further up the incline and for a longer period of time A car with more weight to the rear generally grabs more speed down the slope. Many suggest having the center of gravity at 1 to 11/2 inches in front of the rear wheels. But be careful not to put too much in the rear or you'll pop a wheelie.
What kind of weight? We think the melted lead is dangerous and unnecessary. Tubular weights can be sunk in the sides; flat weights, like those sold at hobby & council stores, can be attached to the car bottom if it is carved in a bit. Incremental weights ( with pre-marked grooves) are easier to snap off into the size you need. Some folks just use BBs, nuts & bolts, etc., but these must be glued so that they can not move. No movable weights or mercury are allowed.
Many like the round weights found at hobby shops and craft stores. This allows you to stick the weights out of the back of the car. Paint them and tell everyone that they are jet engines or tailpipes. What they really do is allow you to get the weights as far back as possible.
Keep the weight low on the car and in the center (Left/Right of the car). Put the weight just in front or behind the rear wheels for less wheel chatter.

Race Day Prepared

Have extra axles and wheels on hand. You never know when your car may be the one dropped by your scout as he shows off his handiwork.
Have a derby tool kit handy. It should include superglue, sandpaper, a drill, extra screws for your weights, extra weights, and a small screwdriver. You may not use it, but it will make you the most popular person at the event.
Transport your car in a shoebox. Dropped cars are unfortunately a too common experience.
Add LOTS of graphite right before check-in.
Explain to your scout that running the car along the floor prior to the race will cause it to lose!